1. Field of the Invention
The present invention relates to an opthalmologic photographing apparatus that enables switching between an infrared light observation and a visible light observation.
2. Description of the Related Art
Generally, an eye fundus photography for capturing an image of a fundus of an eye to be examined includes a non-mydriatic photography for capturing (photographing) an image thereof without a mydriatic agent being instilled into the eye to be examined, and a mydriatic photography for capturing an image thereof with the mydriatic agent being instilled into the eye to be examined are known. In the non-mydriatic photography, the eye fundus photographing is performed by causing the eye to be in state of natural mydriasis in a dark place, and an observation is made using infrared light in order to prevent the pupil of the eye from narrowing (i.e., to prevent miosis) during an observation.
On the other hand, in the mydriatic photography, the eye fundus photographing is performed in a state where the pupil of an eye to be examined is forcibly dilated by the mydriatic agent. In the mydriatic photography, since the miosis does not occur even if visible light is irradiated, an observation with visible light is generally performed. However, the observation may be conducted with infrared light in order to reduce burden to the eye to be examined.
Japanese Patent Application Laid-Open No. 9-66030 discusses a combined machine that can perform both the non-mydriatic photographing and the mydriatic photographing. In the combined machine, an examiner can switch the mode between the non-mydriatic photographing mode and the mydriatic photographing mode. Thereby the photographing is performed by switching the mode to the infrared light observation during the non-mydriatic photographing, and to the visible light observation during the mydriatic photographing.
Fluorescence photography in which the photographing is performed with the fluorescent agent being injected intravenously into the body of an examinee, requires an examination time of normally 10 to 30 minutes or longer. In general, during the initial stage of fluorescence in the fluorescence photography, since the amount of change of an observed image due to inflow of the fluorescent agent is large, a number of photographs need to be taken in a short time. However, during the later stage of the fluorescence in which the fluorescent agent has been circulated throughout the eye fundus, a photographing interval is taken longer since the amount of change of the observed image is small.
In the fluorescence photography, when many examinees are photographed, another examinee may be sometimes photographed during the first examinee's photographing interval during the later stage of fluorescence, in order to enhance the overall photographing efficiency.
Japanese Patent Application Laid-Open No. 2004-180705 discusses an apparatus that can concurrently implement a plurality of examinations in order to handle such cases. However, when the examination that is performed with a photographing apparatus is changed from the examination of an examinee who is undergoing a visible light observation with the mydriatic agent being instilled into the eye, to an examinee who is to undergo an infrared light observation without the mydriatic agent being instilled into the eye, an examiner may forget a mode switching from the visible light observation to the infrared light observation. Further, when the infrared light observation is performed without the mydriatic agent being instilled into the eye, an examiner may switch the mode to the visible light observation by an operational mistake.
When visible light is irradiated to an eye of an examinee who has not undergone instillation of the mydriatic agent, the pupil of the eye may be narrowed. Once the pupil of the eye to be examined is narrowed, a waiting time until the pupil is open again may be needed, and photographing efficiency may be deteriorated.